Struct IndexSlot 

pub struct IndexSlot { /* private fields */ }

The package index of a store, built when first asked for and kept exact by the store’s own revision.

No borrow is held across a call that could come back in: a question asked while another is being answered (a reader that calls another reader) finds the index it is already holding and uses it.

Implementations

impl IndexSlot

pub fn set_partial(&self, partial: bool)

Say that the store is not the whole package: an ETP connection holds what was fetched and nothing else.

The index is then marked incomplete (PackageIndex::is_complete is false: the index of a connection is never complete) - it answers for what was taken, and a caller that needs more asks the server. It does not change what is indexed: the store’s inventory is what it is. Sticky: it describes the store, so a rebuild keeps it, until set_partial(false) is said.

pub fn forget(&self)

Drop the index and any pass in progress; the next question rebuilds.

pub fn revision(&self) -> Option<u64>

The revision the index is exact for, or None when there is none yet.

pub fn node_count(&self) -> Option<usize>

How many nodes the index holds; None when there is no index.

pub fn is_complete(&self) -> Option<bool>

Whether the index covers the store’s whole inventory; None when there is no index.

pub fn take_disturbed(&self, consumer: Consumer) -> Disturbed

What the updates of the index disturbed since this consumer last asked - and forget it. A cache of answers derived from the links asks this inside IndexSlot::with, once the index is exact for the store, and drops what it names (color_walks::ColourCache::disturb, attachments::Cache::disturb).

pub fn with<R>(&self, store: &EpcStore, f: impl FnOnce(&PackageIndex) -> R) -> R

Run f on an index that is exact for store - the invalidation rule of ADR-0010.

No index: build one, in one call. A pass started by IndexSlot::step and unfinished: finish it, then check (the store may have moved since the pass began; the check below re-reads exactly those objects). Otherwise ask the store what changed since the index’s revision: nothing, these uuids, or everything.

An ETP store is an EpcStore like another here; see IndexSlot::set_partial for what it must say about itself.

pub fn step(&self, store: &EpcStore, n: usize) -> Progress

Advance the pass by n objects, and say how far it is - the worker loops, yielding between two slices, so a mesh or a click is answered in the middle of a long pass.

Begins a pass when there is no index, or when the store answers everything changed. When the index exists and only some objects changed, they are re-read at once (that is object-by-object and cheap) and the answer is done. The index is installed the moment the last slice is read; a question asked before then finishes the pass itself (IndexSlot::with), it never answers from half an index.

Trait Implementations

impl Default for IndexSlot

fn default() -> Self

Returns the “default value” for a type.